Answer:
![a_1=3](https://img.qammunity.org/2020/formulas/mathematics/middle-school/5ikd9518nsr7ms5v8n44hchqfc9g1orndd.png)
![a_n = 16 \cdot a_(n-1)](https://img.qammunity.org/2020/formulas/mathematics/high-school/ccct67ir57jf1h2ymqa2lajcxg35a3zvv3.png)
Explanation:
The explicit formula for the geometric sequence is given by:
....[1]
where
is the first term
r is the common ratio of the consecutive terms
n is the number of terms
Given that:
The explicit rule for a sequence is given. by:
On comparing with equation [1] we have;
and r = 16
Use the recursive formula for the geometric sequence is:
![a_n = r \cdot a_(n-1)](https://img.qammunity.org/2020/formulas/mathematics/high-school/xjh9u5cigj3q8j387yrtbe2kci8yjj024s.png)
Substitute the given values we have;
![a_n = 16 \cdot a_(n-1)](https://img.qammunity.org/2020/formulas/mathematics/high-school/ccct67ir57jf1h2ymqa2lajcxg35a3zvv3.png)
therefore, the recursive rule for the geometric sequence is,
![a_n = 16 \cdot a_(n-1)](https://img.qammunity.org/2020/formulas/mathematics/high-school/ccct67ir57jf1h2ymqa2lajcxg35a3zvv3.png)